Crash attenuators are energy absorbing systems that reduce the severity of vehicular collisions, especially the type involving a fast-moving motor vehicle and a road barrier or a highway trailer vehicle. The success of crash impact attenuators is measured by the ability of the devices to limit the extent of injuries suffered by people and the damage done by the equipment as a consequence of such collisions.
Truck trailers typically have a higher elevation than passenger vehicles. This presents a risk that a passenger vehicle will underride the trailer in an accident, potentially resulting in damage to the underriding vehicle and injury to occupants therein. Accordingly, the United States Federal Motor Vehicle Safety Standards require the installation of underride guards or bumpers on certain trailers. The underride guards must comply with certain deflection and energy absorption requirements. Underride guards are common on the rear of trailers; however, underride guards between the landing gear and wheel assembly of the trailer are less common.
A device positioned between the landing gear and wheel assembly of the trailer can function to prevent an impacting vehicle from underriding the trailer. Additionally, such a device can have features to reduce the aerodynamic drag on the trailer.
There have been attempts to address the issues of side underrides. For example, U.S. Pat. No. 5,052,732 that issued to Oplet claims to teach “a crash attenuator [that] includes a plurality of layers . . . of fibrous cellular material. Each of the layers is comprised of a plurality of hexagonal elongate cells fabricated of a fibrous cellulose material that has a longitudinal axis that is disposed horizontal to the ground such that the edge of the cell is directed toward the impacting vehicle. A flat sheet of fibrous material . . . is disposed between each of the layers to provide an energy dispersing surface. A rear impact plate . . . is disposed on the impacting end of the crash attenuator . . . and is fabricated from a soft metal. A front mounting plate . . . is disposed on the opposite end thereof and the two secured by tension cables . . . . The exterior of the layers . . . is covered by sheets . . . . Thereafter, a layer of moisture proof material . . . is disposed over the surface of the crash attenuator . . . to prevent moisture from entering the interior.”
U.S. Pat. No. 6,213,540 that issued to Tusim claims to teach “an energy absorbing article . . . formed of extruded thermoplastic foam . . . [that exhibits high] anisotropic compressive strength. The extrusion direction of the thermoplastic foam is aligned substantially parallel with the direction in which impact resistance is desired to provide an energy absorbing article exhibiting a high ratio of compressive strength to weight.”
U.S. Pat. No. 6,450,556 that issued to Jacobs claims to teach “an external vehicle airbag system . . . , a method of its use and a principal vehicle . . . on which it is mounted [that] involves mounting an airbag . . . at a bottom side . . . of the principal vehicle at a position spaced substantially laterally inwardly from a lateral-side periphery . . . of the principal vehicle. Also involved is a sensor . . . for being mounted on the principal vehicle at a position more laterally outwardly, in a direction toward the lateral-side periphery, than is the airbag. The sensor senses a collision of the principal vehicle with a colliding vehicle and, in response thereto, inflates the airbag below the principal vehicle, along the bottom thereof toward the lateral-side periphery, to thereby absorb energy from the colliding vehicle and prevent under-riding. In one embodiment, the sensor is positioned approximately at the lateral-side periphery and it can be mounted on a rigid under-ride guard.”
German Patent Application Publication No. DE4142804 that issued to Eble claims to teach a “bottom part of the vehicle, between the wheels, . . . [that] is fitted with a tubular frame . . . to which are clipped side panels . . . . These protect pedestrians etc. from running under the vehicle . . . . The panels are removable to access storage lockers, spare wheels etc. The tubular frames . . . have horizontal rails . . . along which the panels can slide. The panels are fitted via clips . . . . The upper mounting can be flexible . . . to enable the panels to be swung up for access to the chassis.”
British Patent Application Publication No. GB2172556 that issued to Brown claims to teach “a sideguard assembly for a commercial vehicle . . . [The sideguard assembly] has a side rail assembly consisting of two parallel spaced apart side rails . . . secured together at one end by a vertical post . . . extending therebetween, the assembly being releasably connected to one or more brackets . . . which in turn are connected to the cross members . . . on the vehicles chassis. The position of connection of the side rail assembly to the brackets is adjustable and the position of connection of the brackets to the vehicles cross members is also adjustable to suit different vehicles.”
World Intellectual Property Organization Patent Application Publication No. WO2005115804 that issued to Ericksson claims to teach “an arrangement for a vehicle side underrun protection comprising at least one loadbearing member, which extends between the wheels or sets of wheels of the vehicle in the longitudinal direction thereof and basically along the outer contour of the vehicle, and which serves as side impact protection and/or protection to prevent unprotected road-users ending up under the vehicle. The side underrun protection . . . comprises at least one longitudinal section . . . suspended in at least two first brackets . . . fixed to the vehicle, along which brackets . . . at least one end of each individual section . . . of the side underrun protection . . . is vertically adjustable from at least a first, active position to a second, inactive position. The invention also relates to a vehicle provided with such a side underrun protection.”
U.S. Pat. No. 8,162,384 that issued to Giromini claims to teach “a side underride cable system configured to be coupled to a trailer includes a front mounting bracket assembly configured to be coupled to the trailer, a rear mounting bracket assembly configured to be coupled to the trailer at a location spaced-apart from the front mounting racket assembly, and a plurality of cables configured to extend at least partially along a length of each side of the trailer between the front mounting bracket assembly and the rear mounting bracket assembly.”
Venkata Kiran Kumar Bodapati's 2004 Master's Thesis titled “Evaluation of Energy Absorbing Pliers Underride Guards for Rear and Side of Large trucks” claims to disclose “two new guards for rear and side [that] are modeled using MSC-Patran and the performance of the guard in preventing passenger compartment intrusion is analyzed using LS-Dyna. A zero-passenger compartment intrusion is achieved with the employment of the newly designed underride guards for rear and side of the trucks. The newly designed guard models are validated using FMVSS 223/224 regulations. The results are in good correlation with the experimental data for rear and the passenger compartment intrusions are reduced in the case of rear and side underride. The performance of the guard is studied at 30, 40 and 50 miles per hour.”